The disclosed invention concerns itself with the production of covered yarn customarily used in the knitting of a portion or all of women's apparel and men's hosiery, an example of which is shown by element 26 in FIG. 9. The term "covered yarn", wherever used in this specification, is used to describe the combination of elastomeric filament or strand about which there is twisted or wound at least one or more "hard fibers." The term "hard fibers" wherever used in this specification denotes a non-elastic filament or spun yarn; for example, 15 or 20 denier nylon.
Covered yarn is currently manufactured by prior art machines called covering machines, examples of which are manufactured by the Officine Meccaniche Menegattio Company of Monza, Italy and the H. H. Arnold Company of Rockland, Massachusetts. These machines are designed to draw an elastomeric filament from a source, wind or twist about the elastomeric filament at least one hard fiber and then wind the thus produced covered yarn on a core, which can be a paper cone or a cylinder, producing what is called in the textile trade a yarn package. Prior to the advent of the disclosure in U.S. Pat. No. 4,137,698, such yarn packages did not have the desirable feeding or draw-off behavior required by knitting machines. Yarn on such yarn packages had the propensity to "hang up" and "pucker" and thus feed unevenly and undesirably in a knitting operation environment. With the advent of the method and apparatus disclosed in U.S. Pat. No. 4,137,698, the contents of which are incorporated herein by reference as if faithfully reproduced, it was found that by using the method and apparatus disclosed a yarn package could be directly produced without having to rewind the covered yarn of the yarn package to achieve the feeding or the draw-off behavior so vitally desired in knitting machines environment. It has often been said: "One can fool a knitter but not a knitting machine."
Prior art textile covering machines pass the elastomeric strand sought to be covered through the center of a spindle on which a package of yarn (hard fiber) is carried for rotation. Such yarn is subsequently twisted about the elastomeric or center strand using a rotating flyer. A typical prior art machine is one manufactured by the H. H. Arnold Company of Rockland, Massachusetts, Model 55-M. Typically, two vertically spaced apart packages of yarn are utilized on vertically spaced apart spindles and the yarns from these packages are wrapped in opposite directions to completely cover the rubber strand. Spindles are driven by belts at a predetermined r.p.m. See U.S. Pat. No. 4,164,113 for more detail description of the H. H. Arnold Company machine referred to above. One important problem U.S. Pat. No. 4,164,113 recognizes is a desire for increased speeds of rotation of the spindles to increase production. The faster one can rotate the spindle and thereby wind or twist the hard fiber around the elastomeric filament, the greater the production within a given unit of time.
Applicant has found when increased spindle speeds are encountered, using spools or reels of prior art design, there is a limitation of just how fast a covering machine can be operated. Spools, reels or pirns (a cylinder) made from metal (iron, steel and/or aluminum for example) or plastic material (thermoplastic, cross-link, or thermosetting resins) rotated at high speeds, such as aluminum above 25, 000 r.p.m. and steel or plastics above 23,000 to 24,000 r.p.m., vibrate and do not achieve a homogeneous wind. At such speeds, a prior art spindle assembly will heat up.
This invention discloses a solution to this problem. Applicant has discovered that a pirn (a cylinder) can be rotated between 13,000 and 70,000 r.p.m. without any of the previously observed prior art drawbacks; however, the surfaces of the pirn must not vary over .+-.0.001 of an inch. Furthermore, Applicant has found that the prior art rotating flyer (see element 15 of U.S. Pat. No. 4,164,113) can be eliminated entirely. The apparatus contemplated by this disclosure is a modified Model 55-M, H. H. Arnold Company machine and consists basicaly of (a) a drive pin assembly; (b) a spindle adapted to receive a cylindrical shaped pirn; (c) a cylindrical shaped pirn the surfaces of which do not vary .+-.0.001 of an inch in which the spindle is axially nested; and, (d) a balloon cap. The balloon cap is a device which in cross-section looks like a nail with a very short shank. It has a cylindrical shank portion integral with a head portion, the shank portion designed so that it can be frictionally engaged and axially nested inside of a terminal portion of the cylinder. The head portion has an overall diameter that is greater than the outside diameter of the cylinder. The opposite end of the cylinder is mechanically received in the receiving means (drive pin assembly), which is essentially the same weight as the balloon cap. Attached to the spindle of the Arnold machine is the drive pin assembly, which imparts rotation to the pirn assembly.
Spindle and pirn speeds up to 70,000 r.p.m. can be achieved; the rotating flyer of prior art machines contemplated by both of the above-identified patents is eliminated; and, a covered yarn package ready to be placed immediately on a knitting machine and having the desired feeding or draw-off behavior can be achieved by this invention. These three improvements over the prior art constitute a device that is not only cheaper (elimination of the rotating flyer) but also increases productivity to extent not heretofore known by the prior art.